Didn't like the portrayal of Jessie at 0:20. "Have fun" doesn't seem much like her. She's supposed to be someone who's really insecure, prone to mistakes and technologically oriented. She likes flashy stuff, but it's mostly from an aesthetic and technological point of view and not some action adrenaline junkie one. She's not supposed to be timid, but she should be a bit more muted or somber. My impression is she's supposed to be a bit older than Cloud, as well, even if it's not confirmed as far as I know.
I also hope the remake allows portraying Jessie, Biggs and Wedge more. We have the basics of their personalities from the little dialogue there is, but would be even better with a bit more relationship building to further make the later moments really impactful. My impression was always that AVALANCHE was a ragtag organization of unprofessionals that was based around anti-Mako extraction and anti-ShinRa sentiments. Supposedly it's supposed to be more than the 5 members we know of, though likely they're not supposed to be that many and with only a core group of active participants (the 5) and likely a few people that work on information gathering. It would likely include people who are anti-ShinRa, as well as those environmentally minded that were inspired by the anti-Mako extraction and general environmental politics of the founder.
When it comes to Barrett we know he's at least a mix of both, he likely joined due to his anti-ShinRa sentiments and was also compatible with the environmental concerns because of what happened to Corel, leading to him easily being inspired by the founder and take his ideas to heart. So fleshing out the other members would be great, including more backstory for AVALANCHE and such.